Lecture 43: Triglycerides and Complex Lipids Flashcards
The synthesis of phosphatidyl lipids requires attachment of an intermediate to
CDP
Gaucher disease can be treated by administration of
Glucocerebrosidase
What is another name for triglyceride?
triacyl glycerol
How do you synthesize triglycerides?
Two fatty acids are transferred from fatty acyl coenzyme A to glycerol 3 phosphate to make a phosphatidic acid.
phosphate group is hydrolyzed
third fatty acyl group is added
How do you make glycerol 3 phosphate?
adipocytes: reduction of glycolytic intermediate (dihydroxyacetone phosphate) using NADH as a coenzyme
liver: glycerol can be phosphorylated by glycerol kinase
T/F: Everything you need for lipid synthesis can be obtained using carbohydrate synthesis.
TRUE.
What are phosphatidyl compounds?
They consist of a phosphatidyl group attached to a polar head group (i.e. alcohol).
What are the two groups of phosphotidyl compounds that can be activated by CDP?
diacylglycerol group
head group
What is another name for phosphatidyl choline?
lecithin
What is special about lecithin?
In its formation, it has an intermediate formation of CDP choline.
What is diacylglycerol involved in?
- synthesis of phosphotidyl molecules
2. synthesis/ breakdown of triglycerides
What do phospholipases do?
They selectively hydrolyze specific ester linkages on phosphotidyl compounds.
What are two important phospholipases?
Phospholipase A2
Phospholipase C
What is the importance of phospholipase A2?
It acts on phosphotidyllinositol and releases arachidonic acid which is an important precursor of prostaglandins.
What is the importance of phospholipase C?
It is activated by the PIP2 system and plays a role in producing second messengers.
What are sphingolipids?
They are fatty acid derivatives of sphingosine
What two molecules is sphingosine synthesized from?
palmitoyl coenzyme A
serine
How do you form a ceramide from sphingosine?
Acylate with a fatty acid transferred from fatty acyl coenzyme A
What does the addition of phosphatidylcholine to ceramide yield?
What if you add sugars?
sphingomyelin
cerebrosides and globosides
What are gangliosides?
They are glycolipids that contain sialic acid.
T/F: Lysgeric acid is the most common monounsaturated acid in the body
FALSE.
Oleic acid is the most common monounsaturated acid in the body.
Where are sphingolipids commonly found?
Cell membrane and particularly in nerve tissue
What generally causes neurological impairment diseases (associated with sphingolipids) like Tay-Sachs?
There are hereditary defects in the enzymes that degrade these sphingolipids and that results in their accumulation
What causes Tay-Sachs disease?
There is a deficiency of the beta hexosaminidase A which causes the accumulation of gangliosides.
What are some symptoms of Tay-Sachs disease?
blindness
muscular weakness
seizures
rapid neurodegeneration
Which disease in the most common genetic diseaseamong the Ashkenazi Jews?
Gaucher disease Type 1
What is the molecular basis of Gaucher disease?
It is caused by a an accumulation glucocerebrosides.
It can be treated by injecting glucocerebrosidase
What are common symptoms of Gaucher disease?
The patients are intellectually okay but they have an enlarged spleen/ liver.
What causes the Newmann-Pick disease?
A deficiency in sphingomyelanase
What is there an accumulation of in Newmann- Pick disease?
sphingomyelin
What are there accumulations of in metachromatic leukodystrophy and Fabry disease, respectively?
sulfatides and globosides
